This invention relates to a fastening member to be employed for a vertical board siding using for instance a ceramic siding board, in which the ceramic siding boards are attached to a building frame with the longitudinal direction of each ceramic siding board being orientated in the vertical direction. This invention also relates to a method of fastening the lower end portion of siding board in the vertical board siding using the fastening member, and to a board siding constructed using the fastening member.
The board siding using a ceramic siding board has been executed either by a horizontal board siding where the siding board is attached to the framework of building with the longitudinal direction of the ceramic siding board being directed in the lateral direction (horizontal direction), or by a vertical board siding where the siding board is attached to the framework of building with the longitudinal direction of the ceramic siding board being directed in the upright direction (vertical direction).
According to the horizontal board siding, as shown in FIG. 11, a moisture permeable waterproofing sheet (or an asphalt saturated felt) 3 is attached at first to a framework consisting of posts 1 and studs 2, and then, in conformity with the longitudinal directions of the posts 1 and studs 2, vertical furring strips 4 are attached to the posts 1 and studs 2 with the moisture permeable waterproofing sheet 3 being interposed therebetween. Thereafter, external wall panels (siding boards) (not shown) are fastened to the vertical furring strips 4, thereby forming a ventilation layer between the moisture permeable waterproofing sheet 3 and the siding boards.
The jointing in vertical direction of the siding boards has been performed either by a method wherein the rabbeted edge portion of a siding board is directly fitted in or engaged with the rabbeted edge portion of another siding board, and then the siding boards are nailed and fixed to the vertical furring strips 4, or by a method wherein instead of the aforementioned engagement between the rabbeted edges of siding boards, a shiplap joint portion of the siding board is fully engaged with a dedicated fastening member, which is then fixed to the vertical furring strips 4 by making use of a nail (or a screw). Since the horizontal board siding employing the aforementioned fastening member is advantageous not only in fastening strength and durability but also in simplicity of executing method, the horizontal board siding is now increasingly employed.
On the other hand, according to the vertical board siding, as shown in FIG. 12, a moisture permeable waterproofing sheet (or an asphalt saturated felt) 3 is attached at first to a framework consisting of posts 1 and studs 2, and then, horizontal furring strips 5 extending across the posts 1 and studs 2 are horizontally attached to the posts 1 and studs 2 with the moisture permeable waterproofing sheet 3 being interposed therebetween, thereby fastening several lines of horizontal furring strips 5 which are spaced apart in vertical direction from each other by a predetermined distance. Thereafter, external wall panels (siding boards) (not shown) are fastened to the horizontal furring strips 5. In this case, a space "s" is provided between the horizontally neighboring horizontal furring strips 5, thereby securing a ventilation passage.
As seen from FIG. 13 showing the horizontal cross-sectional view of a fastening state in this board siding and from FIG. 14 showing the front wall surface of the resultant siding structure, the horizontal jointing between the neighboring siding boards 10 is effected by the engagement between the rabbeted edge portions of the siding boards 10, while the vertical jointing between the vertically neighboring siding boards 10 is effected by making use of a draining metal fitting 6. Further, the fastening of the siding boards has been conventionally performed by means of nailing work using a nail or a screw 11.
Furthermore, in the execution of the board siding at the upper side region of the opening portion "W" such as a window, since the siding boards are not required to be attached to the portion below the upper side of the opening portion "W" as shown in FIG. 12, it is impossible to employ such a fastening means as the draining metal fitting 6 shown in FIG. 14. Therefore, there has been conventionally adopted a fastening method where the lower end portion of the siding board 10 is fixed to a horizontal furring strip 5a by means of nailing as shown in FIG. 15. In FIG. 15, "WS" denotes a window frame (sash).
As described above, according to the vertical board siding, the horizontal jointing between the neighboring siding boards is effected by the engagement between the rabbeted edge portions of the siding boards, the vertical jointing between the vertically neighboring siding boards is effected by making use of a draining metal fitting, and the fastening of the siding boards is performed by means of nailing work. Therefore, in spite of the advantage that a joint sealing work which is required in the horizontal board siding is no more required in the case of the vertical board siding, a large number of relatively short horizontal furring strips are required to be fastened as a backing framework as shown in FIG. 12, so that it necessitates a longer working time as well as an increased material cost, thus giving a great influence to the working cost as well as to the construction period thereof. Further, the position of the external wall surface of building is caused to protrude externally by a distance corresponding to the thickness of the furring strip 5.
Additionally, since the nailing in this case is performed in such a manner that each siding board 10 is individually fixed to the furring strips using a nail 11, the jointing between the horizontally neighboring siding boards is not necessarily sufficient enough. In particular, since the siding boards are vertically fastened, the wind pressure resistive force of the siding boards thus fastened may not be sufficient, if the board siding has not been executed properly according to the prescribed specification for the board siding. Moreover, since the remedy for the head portion of the nail 11 is required after the board siding, the nailing is problematic in terms of aesthetic feeling.
Furthermore, when the siding board is to be fastened to the upper side of an opening such as a window, or to a wall portion where a roof is continuously extended from the lower end portion of the external wall, the siding board is required to be cut to a predetermined length before it is fastened or fixed to such a place. However, as mentioned above, since any siding board which can be utilized as an auxiliary fastening member is not existed below such a place, the fastening of a siding board to such a place is required to be performed by means of nailing while holding the siding board by one's hand.